A device for applying an elongated ribbed strip to the exterior of a rotating conduit

ABSTRACT

A device for the manufacture of externally ribbed heat transfer conduits and/or cores insertable into conduits to provide internally ribbed heat transfer conduit. Means for converting a smooth ribbon into a corrugated ribbon are mounted on a tool holder which in turn is mounted on means pivotable around an axis perpendicular both to the elongated direction of the corrugated ribbon and to the axis of the conduit, or core as the case may be. This pivoting is to enable the ribbon to be wrapped around the conduit, and/or core, in close side to side abutment of the several wraps with respect to each other. The wrapping angle is adjustable from about 45* to about 135* with the 90* position being chosen corresponding to the angle required for a conduit or core approximately midway between the size extremes which a given machine is to handle. A given tool holder and the tools mounted thereon are readily replaceable by lifting one tool holder off the driving gears provided therefor and replacing it with another tool holder.

United States Patent [1 1 Wiedenmann et al. p

[11] 3,789,786 [451 Feb. 5, 1974 [75] Inventors: Konrad Wiedenmann, Staufenring;

Peter Prelisauer, Hafenbad, both of Germany [73] Assignee: Wieland-Werke AG, Ulm, Germany [22] Filed: Mar. 1, 1972 [21] Appl. No.: 230,640

[30] Foreign Application Priority Data Mar. 4, 1971 Germany P 21 10 306.0

[56] References Cited UNITED STATES PATENTS 4/1968 Brown... 29/1573 AH l/l926 Zimmermann 29/202 D Primary ExaminerRichard J. l-lerbst Assistant Examiner-Robert M. Rogers Attorney, Agent, or FirmWoodhams, Blanchard & Flynn [57] ABSTRACT A device for the manufacture of externally ribbed heat transfer conduits and/or cores insertable into conduits to provide internally ribbed heat transfer conduit.

Means for converting a smooth ribbon into a corrugated ribbon are mounted on a tool holder which in turn is mounted on means pivotable around an axis perpendicular both to the elongated direction of the corrugated ribbon and to the axis of the conduit, or core as the case may be. This pivoting is to enable the ribbon to be wrapped around the conduit, and/or core, in close side to side abutment of the several wraps with respect to each other. The wrapping angle is adjustable from about 45 to about 135 with the 90 position being chosen corresponding to the angle required for a conduit or core approximately midway between the size extremes which a given machine is to handle. A given tool holder and the tools mounted thereon are readily replaceable by lifting one tool holder off the driving gears provided therefor and replacing it with another tool holder.

12 Claims, 2 Drawing Figures 1 A DEVICE FOR APPLYING AN ELONGATED RIBBED STRIP TO THE EXTERIOR or A ROTATING CONDUIT diameter are already known. The individual windings of the metallic ribbon are in such cases placed one against the other in the axial direction of the conduit in close abutment with each other and the corrugations of adjacent windings of the metallic ribbon are advantageously arranged in a staggered relationship to each other. The tools which consist of a pair of mating gears are driven in most cases by a chain and the associated sprocket wheels. For this reason the device is mounted rigidly onto a base member.

The above mentioned devices are each only suitable for a single conduit or core diameter. The core consists advantageously of a conduit with or without a plug which serves as a flow seal. The core can, however, advantageously also consist of a-conduit which is grooved on the inside wall or one into which a profile is inserted.

It would also be possible to have a core consisting of a round rod.

If conduits or cores with ribs of different height are to be manufactured, the tool holder must be, movable. 1

This-is required in order to obtain a tangential abutment of the corrugated metallic ribbon on the conduit.

Therefore, there has long existed a need to develop a device on which heat transfer conduits, or externally ribbed'cores of the above mentioned type, with different diameters and ribs of different heights can be manuf actured effectively but with only short retooling time requirements when the product dimensions are to be changed. I

This objective has been attained according to the invention by pivoting the device about a pivot axis which is at a right angle to the center axis of the conduit and extendsthrough the longitudinal axis of the corrugated ribbon, whereby the pivot axis extends through the center axis of the conduit and defined with the longitudinal axis of the corrugated ribbon an angle of approximately to 135..

The angle between the pivot axis and the longitudinal axis of the corrugated ribbon is advantageously approximately 90 during the manufacture of externally ribbed heat transfer conduits, or cores, and having a di- Particularly the driving elements of theftools which consist ofa pair of mating gears can be moved with the device when it is pivoted.

It is furthermore advantageous if the center axis of a shaft which is associated with the driving elements of the tools coincides with the pivot axis. The tool holder is substantially circular.

The substantially circular tool holder is rotatable about an axis which is perpendicular to the longitudinal axis of the corrugated metallic ribbon and is positioned parallel to the transverse axis or plane of the smooth metallic ribbon.

The rotatable, circular tool holder is advantageously supported by two reccesses of the tool holder support.

The two recesses of the tool holder support are advantageously constructed in the form of circular segments, the radius center points of which lie in an axis coincident with the center axis of the circular tool holder.

The tool holder is advantageously pivotable, about its axis at the angle which is required to assure the tangential abutment of the corrugated ribbon on the conduit and the tool holder can subsequently be fixed on the "tool holder support by tightening two clamping screws.

The tool holder can be exchanged advantageously with a different one after the two clamping screws have been loosened and removed by lifting off the same.

This invention eliminates the difficult and time consuming change of tools previously experienced when product dimensions including height of ribs, were to be changed. Further, with this invention, the tool holder also may be coordinated with the tools and accommodated to the desired rib height.

In a preferred embodiment of the invention a separation of the drive between the tool holder and the tool holder support occurs upon removal of a tool holder by lifting off a gear and thus effecting a separation of two mating gears, wherein one gear is supported in the tool holder while the other one is supported in the tool holder support. 7

The advantages achieved with the invention consist particularly in that without long retooling times it is possible to manufacture with one single device externally ribbed heat transfer conduits and cores and it is particularly possible to manufacture same of a variety of selected diameters and rib heights.

Great savings have been achieved by reducing the retooling times and reducing the required equipment to one single device.

One exemplary embodiment of the subject matter of the invention is illustrated in the drawings partly in a simplified manner, namely FIG. 1 is a diagrammatic view of the inventive device during operation thereof with the subsequent wrapping of the corrugated metallic ribbon.

FIG. 2 is a schematic view of the driving elements of the tool holder.

A smooth metallic ribbon 1 is unwound from a reel 35 and is delivered to the tool holder 3 of the device 7. Said smooth metallic ribbon l is then converted into a corrugated metallic ribbon l in the tool holder 3 by guiding the smooth metallic ribbon through a guide piece 11 and thence through and between the teeth of the two mating gears 12 and 13. The gear 13 is driven by a shaft 14 in the direction of the arcuate arrow. A brake mechanism, which is positioned to follow the pair of gears l2, l3 and which can be regulated by a 3 screw 15, is used to control the corrugation length of the corrugated metallic ribbon 2 after passing through the teeth by means of a plastic deformation of the ribbon.

A conduit which serves as a heat-transmitting conduit is identified at 4 and same is to be provided on its outside with longitudinal ribs. The conduit 4 is rotated in the direction of the arcuate arrow adjacent thereto about its longitudinal axis by any convenient means (not illustrated). The conduit 4 is furthermore advantageously moved in direction of the arrow 4a. In order to be able to secure the corrugated metallic ribbon 2 onto the pipe 4, solder in form of a solder ribbon 5 is first wound onto the external surface of the conduit, which solder ribbon 5 is drawn from a reel 6 and runs through a flux container 8.

The conduit is now helically covered by the corrugated metallic ribbon 2 with the interpositioning of the solder. ribbon 5. A satisfactory wrapping with only a small lateral clearance can take place only if the corrugated metallic ribbon 2 approaches at a certain angle which depends on the external diameter of the conduit andthe ribbon width.

This angle is obtained by a suitable pivoting of the inventive device 7 about an axis which is identified with the numeral 9. in order to make possible such pivoting, a pin 30 is secured in the device 7 with its axis coincident with the pivot axis 9 and is supported in any convenient manner, such as in a bearing 29.

This pivot axis is positioned at a right angle to the axis 32 of the conduit and extends through the longitudinal axis 33 of the corrugated ribbon 2, whereby the pivot axis extends through the center axis 32 of the conduit and defines with the longitudinal axis 33 of the corrugated ribbon 2 an angle 36 of approximately 45 to 135. This makes possible the abutment of the corrugated metal band 2 on the conduit 4 always on the same place as seen in longitudinal direction of the pipe.

By suitably rotating the tool holder 3 on the tool holder support 10, a tengential abutment of the corrugated metal ribbon 2 on the conduit 4 is obtained.

'The clamping-screws l6 and 17 (FIG. 2) are now tightened on the tool holder 3. The driving elements of the tools which consist ofa pair of mating gears l2 and 13 are moved with the device when it is pivoted. The driving elements consist in this embodiment of toothed bevel gears 18, 19, 20, 21, gears 22, 23, 24, 25, 26 and shafts 27, 28.

The exchange or replacement of the tool holder 3 is very simple. One only needs to loosen the clamping screws 16 and 17, to remove same and to lift the tool holder 3 off from the tool holder support 10.

The tool holder is inserted by setting it down onto the tool holder support and by fastening the clamping screws 16 and 17. This simple process is surprisingly possible because according to the invention the only connection of the driving elements between tool holder support 10 and tool holder 3 consists of two engaging gears 24, 25. In lifting off the tool holder 3, the mating gears 24, disengage because one gear 24 is sup ported on the tool holder support 10 and one gear 25 on the tool holder 3.

The wrapped conduit 4 is now passed through a conventional heating coil 31 which heats same to create a solder connection between conduit 4 and corrugated metallic ribbon 2. The heating coil 31 encircles the wrapped conduit at any convenient selected distance from the wrapping point.

Eddy currents are produced in the wrapped conduit by applying to it suitable high-frequency alternating current in any conventional manner, which eddy currents heat the conduit at the desired point to the temperature which is required to bring out the desired solder connection. The heating coil 31 remains fixed relative to the wrapping device so that it remains in position although the conduit 4 advantageously moves forward in the direction of arrow 4a.

The device 7 does not only serve, as shown, for the manufacture of externally ribbed conduits for heat transfer, but for example also for the manufacture of externally ribbed cores which can be inserted into conduits for the production of internally ribbed conduits.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A device for applying an elongated ribbed strip to the exterior of a rotating core means; comprising:

means defining an elongated strip supply;

rib forming means engaging said elongated strip and forming ribs thereon, said ribs extending across the width thereof;

support means for supporting said rib forming means for pivotal movement about a pivot axis which intersects and is perpendicular to the longitudinal axis of said core means and for supporting said ribbed elongated strip so that said ribbed strip is wound onto said rotating core means with said ribs extending parallel to the longitudinal axis of said core means;

adjustment means for adjusting the both (1) a first angle between the longitudinal axis of said ribbed strip and said-longitudinal axis of said rotating core means and (2) a second angle between the longitudinal axis of said ribbed strip and said pivot axis, said second angle being maintained in-the range of 45 to 135; and

means for effecting a securement of said ribbed elongated strip to said core means.

2. Device according to claim 16, wherein said second angle is 3. Device according to claim 2 wherein said 90 angle occurs when said longitudinal axis of said strip is perpendicular to the axis of rotation of said core means.

4. Device according to claim 1, wherein support means includes a mounting device and pin means for supporting said mounting device for pivotal movement, the axis of said pin means defining said pivot axis.

5. Device according to.claim 4, wherein said rib forming means includes a pair of meshing rotating gears rotatably secured to said mounting device, said elongated strip passing therebetween, the teeth of said gears deforming said strip to form said ribs thereon.

6. Device according to claim 5, wherein said mounting device includes a tool holder support and a tool holder, said tool holder support engaging said pin means, said tool holder having said gears rotatably secured thereto, and means for supporting said tool holder for rotational movement with respect to said tool holder support.

7. Device according to claim 6, wherein said tool holder support has means defining an arcuate recess therein; and

wherein said tool holder is circular shaped and is rotatably received in said arcuate recess.

8. Device according to claim 7, wherein said tool holder includes means for releasably securing said tool holder to said tool holder support to thereby facilitate a quick removal of said tool holder and the substitution of another tool holder.

9. Device according to claim 8, including a drive gear rotatably secured to said tool holder support and a driven gear rotatably secured to said tool holder, said driven gear being coupled to one of said pair of meshing gears, a separation of said tool holder from said tool holder support effecting a separation of said driven gear from said driving gear.

10. Device according to claim 9, including driven means for driving said drive gear, said drive means comprising a drive shaft coaxial with said pivot'axis and gear train means connecting said drive shaft to said drive gear.

11. Device according to claim'7, including clamping means for clamping said tool holder to said tool holder support.

12. Drive for gears which feed a metallic strip to a device for the manufacture of ribbed conduits which are used as heat exchangers by helically winding up the strip which is fed with its surface approximately parallel to the conduit axis and which prior to the winding up tool means apply the desired ribs by deformation. whereby gears to achieve different screw thread inclinations are pivotable about an axis which is perpendicular to and extends through the point of intersection of the ribbon longitudinal direction with the conduit axis wherein the improvement comprises a drivable shaft having an axis extending through the pivot axis and has a first bevel gear on its upper end, which first bevel gear mates with a second bevel gear which is arranged on a shaft which extends parallel to said ribbon, 'a third bevel gear mounted on said shaft and gear train means for drivingly connecting said third bevel gear to said tools. 

1. A device for applying an elongated ribbed strip to the exterior of a rotating core means; comprising: means defining an elongated strip supply; rib forming means engaging said elongated strip and forming ribs thereon, said ribs extending across the width thereof; support means for supporting said rib forming means for pivotal movement about a pivot axis which intersects and is perpendicular to the longitudinal axis of said core means and for supporting said ribbed elongated strip so that said ribbed strip is wound onto said rotating core means with said ribs extending parallel to the longitudinal axis of said core means; adjustment means for adjusting the both (1) a first angle between the longitudinal axis of said ribbed strip and said longitudinal axis of said rotating core means and (2) a second angle between the longitudinal axis of said ribbed strip and said pivot axis, said second angle being maintained in the range of 45* to 135*; and means for effecting a securement of said ribbed elongated strip to said core means.
 2. Device according to claim 16, wherein said second angle is 90*.
 3. Device according to claim 2, wherein said 90* angle occurs when said longitudinal axis of said strip is perpendicular to the axis of rotation of said core means.
 4. Device according to claim 1, wherein support means includes a mounting device and pin means for supporting said mounting device for pivotal movement, the axis of said pin means defining said pivot axis.
 5. Device according to claim 4, wherein said rib forming means includes a pair of meshing rotating gears rotatably secured to said mounting device, said elongated strip passing therebetween, the teeth of said gears deforming said strip to form said ribs thereon.
 6. Device according to claim 5, wherein said mounting device includes a tool holder support and a tool holder, said tool holder support engaging said pin means, said tool holder having said gears rotatably secured thereto, and means for supporting said tool holder for rotational movement with respect to said tool holder support.
 7. Device according to claim 6, wherein said tool holder support has means defining an arcuate recess therein; and wherein said tool holder is circular shaped and is rotatably received in said arcuate recess.
 8. Device according to claim 7, wherein said tool holder includes means for releasably securing said tool holder to said tool holder support to thereby facilitate a quick removal of said tool holder and the substitution of another tool holder.
 9. Device according to claim 8, including a drive gear rotatably secured to said tool holder support and a driven gear rotatably secured to said tool holder, said driven gear being coupled to one of said pair of meshing gears, a separation of said tool holder from said tool holder support effecting a separation of said driven gear from said driving gear.
 10. Device according to claim 9, including driven means for driving said drive gear, said drive means comprising a drive shaft coaxial with said pivot axis and gear train means connecting said drive shaft to said drive gear.
 11. Device according to claim 7, including clamping means for clamping said tool holder to said tool holder support.
 12. Drive for gears which feed a metallic strip to a device for the manufacture of ribbed conduits which are used as heat exchangers by helically winding up the strip which is fed with its surface approximately parallel To the conduit axis and which prior to the winding up tool means apply the desired ribs by deformation, whereby gears to achieve different screw thread inclinations are pivotable about an axis which is perpendicular to and extends through the point of intersection of the ribbon longitudinal direction with the conduit axis wherein the improvement comprises a drivable shaft having an axis extending through the pivot axis and has a first bevel gear on its upper end, which first bevel gear mates with a second bevel gear which is arranged on a shaft which extends parallel to said ribbon, a third bevel gear mounted on said shaft and gear train means for drivingly connecting said third bevel gear to said tools. 